From 03d01e7d4ffc61c800dc2a65772d86d6e370217d Mon Sep 17 00:00:00 2001
From: Jonas Rembser <jonas.rembser@cern.ch>
Date: Wed, 2 Sep 2026 06:06:47 +0000
Subject: [PATCH] [core] Add missing standard library includes

Several files use std::cout/std::cerr or std::ostream without including
<iostream> or <ostream> themselves, and only compile because
Math/ParamFunctor.h transitively pulls in <iostream>.

Add the includes where they are used, so that ParamFunctor.h can drop its
own <iostream> include without breaking these translation units.

Where a file already listed standard library headers before its ROOT
includes, reorder them to follow the convention of ROOT headers first,
then other libraries, then the standard library.
---
 hist/hist/src/TEfficiency.cxx            | 15 ++++++++-------
 hist/hist/src/TF12.cxx                   |  1 +
 hist/hist/test/test_tkde.cxx             |  1 +
 math/mathcore/test/fit/testGraphFit.cxx  |  1 +
 math/mathcore/test/testDistSampler.cxx   |  3 +++
 test/stress.cxx                          |  4 +++-
 tutorials/analysis/unfold/testUnfold2.C  |  2 ++
 tutorials/hist/hist101_TH1_autobinning.C |  2 ++
 tutorials/math/fit/FitHistoInFile.C      |  2 ++
 tutorials/math/goftest.C                 |  4 +++-
 10 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/hist/hist/src/TEfficiency.cxx b/hist/hist/src/TEfficiency.cxx
index 18ceb70536091..eefa76d5a277c 100644
--- a/hist/hist/src/TEfficiency.cxx
+++ b/hist/hist/src/TEfficiency.cxx
@@ -1,13 +1,6 @@
 #ifndef ROOT_TEfficiency_cxx
 #define ROOT_TEfficiency_cxx
 
-//standard header
-#include <vector>
-#include <string>
-#include <cmath>
-#include <cstdlib>
-#include <cassert>
-
 //ROOT headers
 #include "Math/DistFuncMathCore.h"
 #include "TBinomialEfficiencyFitter.h"
@@ -33,6 +26,14 @@
 // file with extra class for FC method
 #include "TEfficiencyHelper.h"
 
+//standard header
+#include <vector>
+#include <string>
+#include <cmath>
+#include <cstdlib>
+#include <cassert>
+#include <ostream>
+
 //default values
 const Double_t kDefBetaAlpha = 1;
 const Double_t kDefBetaBeta = 1;
diff --git a/hist/hist/src/TF12.cxx b/hist/hist/src/TF12.cxx
index 3ce7ba0939bb3..5d41745e241da 100644
--- a/hist/hist/src/TF12.cxx
+++ b/hist/hist/src/TF12.cxx
@@ -13,6 +13,7 @@
 #include "TH1.h"
 #include "TVirtualPad.h"
 
+#include <ostream>
 
 /** \class TF12
     \ingroup Functions
diff --git a/hist/hist/test/test_tkde.cxx b/hist/hist/test/test_tkde.cxx
index 3d828a9b765eb..0f2fdc0b90d6f 100644
--- a/hist/hist/test/test_tkde.cxx
+++ b/hist/hist/test/test_tkde.cxx
@@ -10,6 +10,7 @@
 #include "TH1.h"
 #include "Math/DistFuncMathCore.h"
 
+#include <iostream>
 
 struct TestKDE {
 
diff --git a/math/mathcore/test/fit/testGraphFit.cxx b/math/mathcore/test/fit/testGraphFit.cxx
index e04772e4f4048..0b8efc9e82149 100644
--- a/math/mathcore/test/fit/testGraphFit.cxx
+++ b/math/mathcore/test/fit/testGraphFit.cxx
@@ -20,6 +20,7 @@
 #include "TStyle.h"
 
 #include <vector>
+#include <iostream>
 #include <iterator>
 #include <cassert>
 
diff --git a/math/mathcore/test/testDistSampler.cxx b/math/mathcore/test/testDistSampler.cxx
index 2e32a475c2066..86e2b4d082acc 100644
--- a/math/mathcore/test/testDistSampler.cxx
+++ b/math/mathcore/test/testDistSampler.cxx
@@ -9,6 +9,9 @@
 #include "TRandom.h"
 #include "TError.h"
 #include "TCanvas.h"
+
+#include <iostream>
+
 // double Pdf(double x) {
 // }
 
diff --git a/test/stress.cxx b/test/stress.cxx
index b52e6600a02cd..51c814e2ff9a7 100644
--- a/test/stress.cxx
+++ b/test/stress.cxx
@@ -71,7 +71,6 @@
 //_____________________________batch only_____________________
 #ifndef __CLING__
 
-#include <cstdlib>
 #include <TROOT.h>
 #include <TSystem.h>
 #include <TH1.h>
@@ -100,6 +99,9 @@
 #include <snprintf.h>
 #include "Event.h"
 
+#include <cstdlib>
+#include <iostream>
+
 void stress(Int_t nevent, Int_t style, Int_t printSubBenchmark, UInt_t portion );
 void stress1();
 void stress2();
diff --git a/tutorials/analysis/unfold/testUnfold2.C b/tutorials/analysis/unfold/testUnfold2.C
index 6c997314b268c..c1e6fa8fa6ee5 100644
--- a/tutorials/analysis/unfold/testUnfold2.C
+++ b/tutorials/analysis/unfold/testUnfold2.C
@@ -78,6 +78,8 @@
 #include <TGraph.h>
 #include "TUnfold.h"
 
+#include <iostream>
+
 
 TRandom *rnd=nullptr;
 
diff --git a/tutorials/hist/hist101_TH1_autobinning.C b/tutorials/hist/hist101_TH1_autobinning.C
index dc19339939595..f3f838d716710 100644
--- a/tutorials/hist/hist101_TH1_autobinning.C
+++ b/tutorials/hist/hist101_TH1_autobinning.C
@@ -19,6 +19,8 @@
 #include "TFile.h"
 #include "TStyle.h"
 
+#include <iostream>
+
 TF1 *gam = new TF1("gam", "1/(1+0.1*x*0.1*x)", -100., 100.);
 TF1 *gam1 = new TF1("gam", "1/(1+0.1*x*0.1*x)", -1., .25);
 TF1 *iga = new TF1("inv gam", "1.-1/(1+0.1*x*0.1*x)", -100., 100.);
diff --git a/tutorials/math/fit/FitHistoInFile.C b/tutorials/math/fit/FitHistoInFile.C
index 2b79f43513dbd..50f9dd07789d6 100644
--- a/tutorials/math/fit/FitHistoInFile.C
+++ b/tutorials/math/fit/FitHistoInFile.C
@@ -19,6 +19,8 @@
 #include "TFile.h"
 #include "TStyle.h"
 
+#include <iostream>
+
 // Function parameters are passed as an array to TF1. Here, we
 // define the position of each parameter in this array.
 // Note: N_PAR will give us the total number of parameters. Make
diff --git a/tutorials/math/goftest.C b/tutorials/math/goftest.C
index 8d36e2071ed7d..256fb796a1545 100644
--- a/tutorials/math/goftest.C
+++ b/tutorials/math/goftest.C
@@ -13,7 +13,6 @@
 ///
 /// \author Bartolomeu Rabacal
 
-#include <cassert>
 #include "TCanvas.h"
 #include "TPaveText.h"
 #include "TH1.h"
@@ -23,6 +22,9 @@
 #include "TRandom3.h"
 #include "Math/DistFunc.h"
 
+#include <cassert>
+#include <iostream>
+
 // need to use Functor1D
 double landau(double x) {
    return ROOT::Math::landau_pdf(x);